Many reports over the past 15 years indicate that there has been an increase in the prevalence of enamel fluorosis in both fluoridated and nonfluoridated U.S. populations. Research conducted during the first five years of this investigation suggests that fluoride ingestion during toothbrushing, infant formula use, and the inappropriate use of fluoride supplements, by young children living in fluoridated areas are important, strong risk factors for mild-to-moderate enamel fluorosis. The observation of a fluorosis prevalence increase, along with evidence of specific risk factors has led to extensive discussion on the most appropriate recommendations for fluoride use in the 1990's and beyond. To date, however, fluorosis risk factor studies have been conducted on primarily Caucasian populations, or have not reported race information. As discussions occur related to possible modifications in dental public health recommendations related to fluoride use, it is important that the underlying research base for those discussions include the broadest racial and socioeconomic base. To that end, this proposed case-control epidemiologic investigation will investigate the association between fluoride toothpaste, infant formula use, and inappropriate fluoride supplement use, and mild-to-moderate enamel fluorosis in a middle-school population with significant African-American and Hispanic representation. The portion of fluorosis attributable to specific risk factors will also be estimated based upon the adjusted multivariate analyses, as will the association between fluorosis status and dental caries. The goal of this research is directly in line with the current NIH programmatic initiative to promote the involvement of women and minorities in human subject research. Methodologies successfully used in three previous investigations will be used in this study, including the use of the Fluorosis Risk Index, developed specifically for use in analytical epidemiologic studies, and a questionnaire which has repeatedly yielded a high response rate (approximately 90%), high level of reliability (85-90%) and the ability to allow strong age-specific fluorosis risk factors to be identified.